Method of making solder connections



Jan. 19, 1943. w. E. INGERSON 2,308,606

METHOD OF MAKING SOLDER CONNECTIONS Filed May 8. 1941 7 heets-Sheet l FIG. 23

. y, FIG. 24

lNl ENTOR W E lNGERSON A TTOPNEV Jan. 19, 1943. w. E. INGERSON 2,308,606

METHOD OF MAKING SOLDER CONNECTIONS Filed May 8, 1941 7 Sheets-Sheet 2 FIG. 2

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Filed May 8, 1941 7 Sheets-Sheet 3 llll I INVENTOP By M. 5 //vaRs0/v ATTORNEY Filed May a, 1941 W. E. INGERSON A 7' TORNEV FIG.

. /N 5 N TOR m5. INGERSON 9 7m amid FIG. /4

METHOD OF MAKING SOLDER CONNECTIONS FIG. /2

Jan. 19, 1943.

Jan. 19, 1943. w. E. INGERSON METHOD OF MAKING SOLDER CONNECTIONS Filed May 8, 1941 7 Sheets-Sheet 5 1||||||||||Im| W N mmm max VW Q WE fin am WJ Jan. 19, 1943. w. E. INGERSON 2,308,606

AETHOD OF MAKING SOLDER CONNECTIONS Filed May 8, 1941 7 Sheets-Sheet 6 FIG. /8

FIG. /9

lNl ENTOR W. E INGERSON A TTORNEV Jan. 19, 1943. w. E. INGERSON METHOD OF MAKING SOLDER CONNECTIONS Filed May 8, 1941 7 Sheets-Sheet '7 v, E NW N 0 R mm m m max A W m /E 2% w yaw/4%.

Patented Jan. 19, 1943 METHOD OF MAKING SOLDER CONNE CTIONS William E. Ingerson, New York, N. 2., assilnor to Bell Telephone laboratories, Incorporated ,New

York, N. 1, a corporation oi New York Application May 8, 1941, Serial No. 392,505

3Claims.

This invention relates to a method of securing a wire to a metal surface.

The invention is applicable to the securing of wires of relatively fine gauge to metal surfaces formed on piezoelectric crystals.

In accordance with this invention a disc of solder of predetermined size and form is made. The disc is picked up by the end of the wire and is placed on a required point on a metal surface formed on a piezoelectric crystal. A heated tool is then placed in contact with the disc to make the disc form a solder connection between the wire and the metal surface on the crystal.

In the drawings:

Fig. 1 is a view in perspective of the apparatus devised for making the solder connections, the apparatus parts being mounted on a support in a convenient arrangement for use;

Fig. 2 is an enlarged top view of a wire holding chuck and a portion of the support shown in Fig. 1;

Fig, 3 is a side view, partly in section, of the chuck shown in Fig. 2; v

Fig. 4 is a top view of a portion of the apparatus shown in Fig. 3 and taken on the line 4-;

Fig. 5 is a top view of a portion of the chuck and showing the jaws thereof;

Fig. 6 is an enlarged view of an end portion of Fig. 5;

Fig. 7 shows an end portion of Fig. 6 but with the jaws in a closed condition;

Fig. 8 is a side view of Fig. 7;

Fig. 9 is an end view, in section, of Fig. 8 and taken on the line 8-9;

Fig. 10 is a side elevational view of a punch device used in making the discs of solder and shows two positions of a movable punch head;

Fig. 11 is an end view of the device shown in Fig. 10 and shows two positions of the plunger;

Fig. 12 is a top view of the-punch device;

Figs. 13, 14 and 15 are enlarged views,- partly in section, of portions of the punch device with a piece of sheet solder therein and showing three positions taken by the plunger;

Fig. 16 is an enlarged side view, partly in section, of a portion of the chuck, a portion of the punch device and with a wire held in the chuck and inserted in the punch device;

Fig. 17 is a top view of a hot plate device equipped with means for adjusting and holding a crystal in required position; I Fig. 18 is a front elevational view of the device shown in Fig. 17 and taken on the line ll-li;

Fig. 19 is a view, partly in section, taken on the line lQ-IS in Fig. 17 and shows a thermostat provided in the hot plate device; a

Fig. 20 is a side view, in section, of the-hot plate device and taken on the line 20-40 in Fig. 1'7;

Fig. 21 is a front view, in section, of the hot plate device and is taken on the line 2l-2i of Fig. 17;

Fig. 22 is a view, in section, of a portion of the hot plate taken on the line 22-22 in Fig. 17;

Fig. 23 shows a fragmentary portion of the chuck with a wire held therein and a disc of solder picked up by the end of the wire;

Fig. 24 shows a portion of a crystal with the wire solder-connected thereto; and

Fig. 25 is a top view of the parts shown in Fig. 24.

The punch device is covered in a divisional application of this case Serial No. 433,475, filed March 5, 1942, and the hot plate device and the heated tool used in cooperation therewith in making the solder connection are covered in a divisional application of this case Serial No. 434,521, filed March 13, 1942.

In solder-connecting a wire of relatively fine gauge to a metal surface provided on a piezoelectric crystal, it is important that the wire be connected at the particularly desired point on the crystal; also that the solder connection made is of a predetermined size and form and is sufilciently strong to permit use of the wire as a supporting means for the crystal. It is also important that the wire be not sufllciently affected by the heat applied in making the solder connection as to cause embrittlement or annealing of the wire and that the crystal be not subjected to reactive forces or thermal gradient suilicient to cause fracturing of the crystal.

The apparatus shown in the drawings is constructed and arranged to make solder connections in accordance with the invention and as shown in Fig. 1 comprises a punch device 26, a chuck 21, a hot plate device 28, a heated tool 29 and a reel support 30, all of which are mounted on a suitable support 3|. The hot plate device 28 is shown as supporting a crystal 32. The wire 35 is held in the chuck 21 so that the disc of solder on the end of the wire is in contact with the stripe 34 of with a metal stripe I4 thereon is placed on the hot plate device 28 and is adjusted on the hot plate device to a required position. An end portion of the wire 35 is threaded through jaws of the chuck 21 and so that a required length of the wire 35 projects below the jaws of the chuck. A suitable flux is applied to the downwardly projecting end portion of the wire and this end portion of the wire is then brought into contact with a predetermined point on the metal stripe 34 and so that some of the flux will be deposited on the metal stripe 34. The chuck 21 is then rotated to bring the downwardly projecting end of the wire 35 in register with an aperture provided in the punch device 28 containing the disc of solder. The end of the wire is thrust into the disc of solder so that the disc of solder will be frictionally held and centrally located on the end of the wire. The chuck is then rotated back to a position over the crystal 32 and the disc of solder is brought into engagement with the fluxed portion of the metal stripe 34. The heated tool 29 to which solder will not adhere is then rotated to bring its hot point 38 into contact with the disc of solder. The heat from the tool 29 melts the disc of solder so that the disc of solder will form a solder connection between the end of the wire 35 and the metal stripe 34. Since the end of the wire 35 was previously treated with a suitable flux, the molten material obtained by heating the disc of solder will have a tendency to flow upwardly along the wire 35 and will solidify on the end of the wire 35 in the form of a cone 3'! when the heat is removed. The cone-shaped solder connection 31 obtained is shown in Fig. 24. Fig. 23 shows the disc 38 of solder on the end of the wire 35 before the disc is melted to obtain the solder connection 31. The hot plate device 28 is equipped with heating means and is maintained at a temperature slightly below the melting point of the solder disc 38 so that the crystal 32 will be maintained at an elevated temperature during the making of the solder connection. This prevents fracturing of the crystal 32 when the solder connection is being made. Maintaining the crystals at the elevated temperature reduces the reactionary eflects upon application of the heated tool 36 to the crystal 32. After the solder connection is made the wire 35 may be severed at a predetermined point to leave a portion of the wire solderconnected to the crystal as shown in Fig. 24. A suitable supply of the wire 35 is contained on the spool 38 which is rotatably mounted on the reel support 38.

Punch device The punch device 25, Fig. 10, may be used in making the disc 38 of solder. It comprises a pair of spaced upright supports 39 and 48, a horizontal plate 4| supported between the plates 39 and 48 by means of the screws 42, and a reciprocating punch-head 43 slidably supported on the horizontal plate 4|. The punch-head 43 may be manually slid along the plate 4| to required positions and is held against dislodg- I ment from the plate 4| by means of screws 44 which extend through elongated apertures 45 in the plates 39 and 48. Two extreme positions taken by the punch-head 43 are shown in Fig. 10, the full line position being the position taken by the punch-head 43 when the punch device is used in punching out a disc 38. The punchhead 43 is apertured at 45 to accommodate a plunger device 41 on the lower end of which is supported a punch 48, the punch 48 being adapted to punch out a disc 38 of predetermined size 2,sos,eoe

and form from a sheet 49 of solder foil. The punch-head 43 may be made in the form of a block and is transversely slotted at one end to provide an operating space 58 in which the strip 49 may be fed under the punch 48. A die 5| is supported in the punch-head 43 directly below and in register with the punch 48, the die 5| having an aperture 52 provided therein to slidably receive the punch 48 so that the die 5| and the punch 48 may be used in cooperation to punch out the discs 38 from the strip 48 of solder. The upper end of the die 5| extends upwardly within the space 58 so that a portion of the sheet 48 must be slightly elevated to pass over the upper portion of the die 5| as shown in Figs. 11, l3, l4 and 15. Two guide pins 53 are mounted in the punch-head 43 and extend into the operating space 58, the guide pins 53 being mounted in spaced relation and having downwardly extending ends 54 extending below the upper level of the die 5|. The horizontal plate 4| is apertured at 55 directly below the lower end of the die 5|, the aperture at 55 being of such form and dimensions that it will accommodate the disc 38 stamped out from the sheet 49. A plug 56 is provided in the aperture 55 and the upper end of the plug 55 is spaced below the upper surface of the plate 4| a suflicient distance to accommodate the thickness of the disc 38. As shown in Fig. l0 the punch-head 43 may be manually slid along the plate 4| from the dot-dash line position to the full line position shown in this figure, the extent of travel being limited by the screw 44 operating in the slot 45. When the punch-head 43 is in the full line position the punch 48 and the die 5| are directly over and in register with the aperture 55 provided in the plate 4|. In this position the plunger 41 may be manually operated to press the punch 48 through the sheet 49 and the die 5| to punch out a disc 38 from the sheet 49, the disc 38 being deposited in the aperture 55 and resting on the top of the plug 56 in the horizontal plate 4|. After the disc 38 has been punched out and pressure is released from the knob 51 provided on the top of the plunger 41 and the plunger 41 has been returned to its elevated position by means of the spring 58, 'the punch-head 43 may be slid along the plate 4| to the dot-dash line position shown in Fig. 10. Fig. 13 shows the punch 48 in its elevated position; Fig. 14 the punch 48 thrust through the sheet 49 and carrying the disc 38 downwardly within the die 5|. Fig. 15 shows the disc 38 deposited on top of the plug 55 where it will remain during the sliding back of the punchhead 43 and until it is picked up on the end of the wire 35 shown in Fig. l and Fig. 23. It will be seen by looking at Figs. 11 and 13 that the sheet material 49 passes over the upper edges of 39 and 48 and under the portions 54 of the pins 53 and then over the upper end of the die 5| and that by reason of the frictional engagement of the sheet material 49 with the other parts mentioned the sheet material 49 is held in suiiicient tension across the upper end of the die 5| to permit punching out of the disc 38 by means of punch 48. After a disc 38 has been punched out from the sheet material 49 the sheet material 49 may be moved across the upper end of the die 5| to obtain a new area for punching out another disc 38. When a disc 38 has been punched out from the sheet material 49 and is resting on the plug 58 and the punch-head 43 is moved to the dot-dash line position shown in Fig. 10, the disc 38 may be picked up by an end of the wire 88 held in the chuck 21, as shown in Fig. 16, i

by bringing the end of the chuck 21 holding the wire 85 over the disc 38 and then by pressing downwardly on the free end of the chuck 21 to thrust the wire 35 into the disc 38.

Chuck The chuck 21 as shown in Figs. 1, 2 and 3 is constructed and arranged to hold an end of the wire 85 in a plurality of required positions and comprises an arm 58 equipped with jaws 88 and 8| arranged and supported on the undersurface of the arm 58, the jaw 88 being fixedly supported in position by means of a pin 82 and a screw 83. The jaw 8| is pivotally supported on a pin 88 mounted on the undersurface of the arm 58 and is movable relative to the jaw 88. The jaw 8| is much longer than the jaw 88 and is operated by means of a manually operated cam 85 equipped with a turning knob 88. When the cam 85 is rotated to bring a high spot thereon against the rear portion of the jaw 8| the jaw 8| is moved against the action of a spring 81 to bring the gripping ends 88 of the jaws together so that the wire 35 may be clamped therebetween. Rotation of the cam 85 to another position will permit the spring 81 to open the gripping ends of the jaws. Spaced pins 88 and 18 are provided on the cam 85 to limit rotation of the cam 85 to open and closed positions. A tapered bracket 1| partially encloses the operating ends of the jaws 88 and 8|, the bracket 1| as shown in Fig. 9 having portions. extending across the upper and lower surfaces of the jaws 88 and 8| and a portion extending down the side of the jaw 88. The lower portion of the bracket 1| is apertured to accommodate and hold an apertured tip 12 which is made of material to which solder will not adhere, the tip 12 being longitudinally bored to receive the wire and the upper portion of the tip being formed to fit into a countersunk aperture in the bracket 1|. The upper portion of the bracket is apertured at 13 to accommodate the wire 35. The bracket 1| is provided with an elongated slot 14 and is adjustably supported on the side of the jaw 88 by means of a screw 15 which extends through the aperture 14 and into the jaw 88. The bracket 1| may be adjusted on the jaw 88 so that the tip 12 and the wire 35 extending therethrough may be brought to a required point on the crystal or over the aperture in the punch device 28 when the chuck 21 is moved into position over the punch device 28 or the hot plate device 28. The arm 58 is mounted on a shaft 18 which is supported for rotational and longitudinal movement in a bearing 11 secured in the support 3|, the shaft 18 being equipped with a knob 18 by means of which the shaft 18 may be lifted in the bearing 11 and rotated therein. The lower end of the shaft 18 is engaged by a lever 18 equipped with an adjustable counterweight 88 and is fulcrumed in a bracket 8| which is supported on the undersurface of a plate 82 secured to spaced pillars 83 extending from the lower surface of the support 3|, the pillars 83 being held in place by screws 84. Spaced pins 85, 88, 81 and 88 are mounted on the upper surface of the plate 82. A positioning plate 88 equipped with an apertured boss 88 is mounted by means of the set screws 8| on the shaft 18, the plate 88 being apertured to receive the studs 85, 88, 81 and 88 and providing a means for holding the arm 58 in required positions over the punch device 28 or the hotplate device 28. when the arm 58 is swung over to a position over the punch device 28 the stud 85 is engaged in an aperture provided in the free end of the positioning arm 88 and the studs 81 and 88 are engaged in apertures 82 and 83, respectively, in the other end of the positioning arm 88. This will hold the jaws of the chuck 21 in required position over the punch device 28. The chuck 21 may be rotated so that the jaws will be moved from this position and to a position over the hot-plate device 28 by lifting up on the knob 18 so that the arm88 is brought out of engagement with the studs 85, 81 and 88. {The chuck may then be rotated to bring it over the hot-plate device 28 and so that the aperture in the free end of the arm 88 will be engaged by the stud 88 and the apertures 83 and 88 provided in the arm 88, will be engaged by the studs 81 and 88, respectively. It will be seen that the counterweight 88 may be adjustably supported on the lever 18 so that its weight will almost counterbalance the weight of the chuck 21. will relieve the wire 35 from most of the weight of the chuck 21. An adjustment screw 85 and a lock nut 88 are mounted on the plate 82 to engage the positioning plate 88 and prevent undue lowering of the chuck 21 when the chuck 21 is positioned over the punch device 28. Another adjustment screw 85 equipped with a lock nut 88 is also provided at a required point to prevent undue lowering of the chuck 21 when it is in position over the hot-plate device 28.

Hot-plate device The hot-plate device 28 is used to support the crystal 32 while an end of the wire 35 is being solder-connected to a metallized surface 34 on the crystal 32 and is provided with adjustable positioning means to move the crystal to its desired position and hold it in that position while the solder connection is being made. As shown in Fig. 1, the hot-plate device 28 is positioned within a relatively large rectangular opening 81 provided in the support 3| and comprises a round table 88 and a rectangular frame plate 88, the upper surfaces of the table 88 and the plate 88 being in the same plane. An elongated aperture I88 is provided in the table 88 for a purpose to be later explained. As shown in Fig. 17, the table 88 is provided with cartridge type heating elements |8I which may be supplied with electrical current from a, suitable source of supply, not shown, to heat the table 88 to a required temperature, the heating elements I8I being located The slide bars I85 rest on spaced tracks I81 undersurfaces of the tracks I81.

which are cylindrical in cross section, the slide bars I being transversely grooved on their lower surfaces as shown at I88 to accommodate the tracks I81. Leaf springs I88 secured by means of screws II8 to the undersurface of the slide bars I85 are provided to retain the slide bars I85 on the tracks I81, the springs I88 having curved end portions to frictionally engage the The tracks I81 are longer than the aperture 81 in the support 3| and are secured at their ends by means of screws III as shown in Fig. 20 to crosspieces H2. The bars I85 are apertured to accommodate an adjustment rod I I3 which is journaled in one of the crossbars H2 and provided with retaining col- This lars H4 and H5. The inner end of the rod H3 is externally threaded as shown at I I6 and one at least of the bars I is internally threaded to receive the thread on the rod H3. The adjustment rod H3 is equipped with a manually operated knob II1 so that the adjustment rod II3 may be manually rotated. The table 99 may be -made of aluminum or other good heat transmitting material and rests on an insulating plate II8 as shown in Fig. 21, which rests on the slide bars I05, the table 98 and the insulating ,plate I I8 being secured in place by means of screws I I9 which extend through apertures in the slide bars I05, through suitable apertures in theinsulating plate H8 and into threaded engagement with the table 98. The table 96 and the frame plate 99 may be moved backward and forward within the aperture 91 by suitable rotation of the adjustment rod II3. It will therefore be apparent that if a crystal 32 is supported on the table 98, the table 98 and the frame plate 99 may be moved as a whole either backward or forward within the aperture 91 to bring the crystal or a predetermined point thereof into a desired position relative to an end of the chuck 21 when the chuck 21 is swung into overlying position relative to the hot-plate 28. The hot-plate 29 is also equipped with relative y long positioning fingers I and I2I to further adjust the crystal 32 to a required position and to hold the crystal in the position required. The fingers I20 and I2I are arranged in parallel spaced relation and extend across the upper surface of the table 90 and the frame plate 99 and may be moved toward or away from each other by operation of a manually rotatable adjustment screw I22 equipped with a turning knob I23. The screw I22 has right and left-hand thread portions engaging suitably threaded sleeves I24 and I25 which are slidably supported in a longitudinally apertured block I26. The block I26 is supported on flat bars I21 and I28 extending from the front edge of the frame plate 99 and which are secured to the undersurface of the plate 99 by means of the screws I29, the bars I21 and I28 being secured by means of the screws I30 to the undersurface of the block I26. A slideway I3I is provided in the rear wall of the block I26 to accommodate widened portions of the fingers I20 and I2I, the slideway I3I being in communication with the longitudinal bore I32 provided in the block I26. When the knob I23 is rotated in one direction, the fingers I20 and I2I are moved toward each other by means of the threads on the shaft I22 and the sleeves I24 and I25, the widened ends of the fingers I20 and I2I being secured in suitable slots I33 provided in the sleeves I24 and I25 as shown in Fig. 22. Manual rotation of the knob I23 in the opposite direction will cause the fingers I20 and I2I to be moved away from each other. An elongated slot I34 is formed in the front portion of the block I26 and screws I35 are provided in the block to regulate the frictional engagement of the side walls of the aperture I3I on the portions of the fingers I20 and I2I extending therethrough, the screws I35 being extended transversely across the slot I 34 and having screw-threaded engagement with the portion of the block I26 lying below the slot I34. When the screws I35 are tightened the portions of the block I26 lying above and below the slot I34 are drawn toward each other, It will be seen that since the slot I34 extends almost to the bore I32 in the block I26, tightening of the screws I35 will have the effect of slightly widening the aperture I3I and allow the flngers I20 and I2I to more freely slide in the aperture I3I. The screws I35 may be used therefore to reduce or. increase the frictional engagement of the walls defining the aperture I with the fingers I20 and I2I to a required extent. The tracks I01 are supported on spaced ties I35 and I31 and are secured thereto by means of the screws I30. The ties I36 and I31 are secured by means of screws I39 to a flexible plate I40 supported at its ends on pillars HI and I42 and the plate I40 is held in spaced relation with the support 3| by means of the pillars I43 and I44. The pillars I4I, I42, I43 and I44 are longitudinally bored and are held in place by long bolts I45 which also pass through the support 3|, the pillars, the flexible plate I40 and a rigid plate I43. It will be seen by looking at Fig. 18 that the rigid plate I46 is suspended from the support 3I by means of the long bolts I45 which are equipped with nuts I41 to hold the parts in assembled condition. A bolt I46 is secured in about the central portion of the flexible plate I40 and extends downwardly through the rigid plate I46 and is equipped with a relatively large knurled nut I49 to provide means for adjusting the table 93 and the frame plate 99 upward and downward relative to the support 3I. Turning of the nut I49 in a clockwise direction will cause downward flexing of the flexible plate I40 and consequent slight lowering of the table 98 and the frame plate 99. When the nut I49 is turned in a counterclockwise direction the flexible plate I40 will resume its normal position and slightly elevate the table 99 and the frame plate 99. The slot I00 provided in the table 96, as shown in Fig. 17,

4 extends more than half the distance across the table 96 and through the entire thickness of the table. The upper edges of the-walls defining the elongated aperture I00 are cut back to provide shoulders I50 to serve as a rest for a positioning block I5I through which a holding screw I52 extends. The lower end of the screw I52 as shown in Fig. 21 is provided with a large flat head I53 which extends in overlapping relation with the edges of the aperture I00 and into a slot I54 provided in the insulating plate III. The upper end of the screw I52 is kerfed to permit turning of the screw within the block I5I which may be adjusted along the aperture I00 to provide a back stop for the crystal 32. The aperture I00 also provides a space in which wires already attached to a crystal may extend while a wire is being attached to the other side of the crystal. A thermostat I55 is provided to control the supply of current to the heating elements Ill, the thermostat I55 being of the bi-metallic element type and being located in a suitable slot provided in the table 93. The thermostat I55 as shown in Fig. 19 may be adjusted by means of the screw I56 so that its contacts will open and close at required temperatures.

Heated tool The heated tool 29, as shown in Fig. 1, somewhat resembles an electric soldering iron. The hot point 36 of the tool, however, is made of aluminum or some other heat transmitting material to which solder will not adhere. Thetool is held in a clamp I51 which is pivotally supported in a yoke I53, the yoke I50 being pivotally supported on a post I59 provided with a base I60 which is secured by means of screws I6I to the support 3|. A heating element in the tool may be supplied with current through a conductor core I62 which may extend from a suitable source of current supply, not shown.

In solder-connecting a wire to the crystal 32 a suitable metal surface is first provided on the crystal 32. This metal surface may be in the form of a stripe of solder applied across one of 29 is brought into engagement with a portion of the disc 38, the tip 36 of the tool 28 being the flat surfaces of the crystal and at a nodal point of the crystal or at any other point re- I quired. A disc of solder of predetermined size and form is punched out f1 om a sheet 49 of solder foil by means of the punch device 26, the punchhead 43 being moved over into a position in which the punch 48 may be thrust through the sheet 49 and moved-to deposit the disc 38 in the holding space 55. The punch-head 43 is then moved along the plate 4| so that it no longer covers the disc 38, the punch-head being moved to the dot-dash line position shown in Fig. 10. An end of the wire 35 is led through the jaws of the chuck 21 and through the tip 12 so that a predetermined length of the wire 35 extends below the tip 12. The jaws of the chuck are then closed by operation of the knob 66 to hold the downwardly projecting end of the wire in required position. Asuitable soldering fiux is then applied to the end of the wire. The crystal 32 is adjusted on the hot-plate device 28 to a required position by means of the fingers I28 and HI which may be brought toward each other to engage opposite sides of the crystal 32 by operation of the knob I23. The hot-plate I device 28 may be then moved as a whole by operation of the knob H1 to move the hot-plate device 28 forward or backward as required to bring a particular point on the stripe 34 on the-crystal directly under the end of the wire when the chuck 21 is in the position shown in Fig. 1. tal 32 may be also adjusted on the table 98 by moving the stop I51 to a required position. Further relative adjustment of the parts to be connected may also be made by moving the bracket 1| holding the tip 12 through which the wire extends. When all the parts have been set so that the downwardly projecting end of the wire 35 is directly over the required point on the stripe 34, the chuck 21 is moved downwardly so that the fluxed end of the wire 35 comes into contact with the stripe 34 and so that some of the flux from the wire will be deposited on the stripe 34. The chuck 21 is next rotated by manual turning of the knob 18 to bring the downwardly projecting end of the wire 35 directly over the aperture 55 in the punch device 26. The chuck is then lowered so that the end of the wire slightly pierces the disc 38 of solder held in the punch device 26, the extent of lowering of the chuck 21 being limited by a screw I63 adjustably mounted on the support 3|. Chuck 21 is then lifted so that the disc 38 will be lifted from the punch device 26 and carried by the end of the wire out of the punch device 26. The chuck 21 is then rotated to the position shown in Fig. l and is lowered again so that the disc 38 comes into contact with the iluxed portion of the stripe 34 on the crystal 32. It is to be understood that during these operations the hot-plate device 28 is maintained at a required temperature and that the crystal 32 resting thereon is heated to a temperature slightly below the melting temperature of the solder disc 38 and below the melting temperature of the material in the stripe 34. When the disc 38 is placed on the stripe 34 the heated tool 29 is swung from the position shown in Fig. l and over the course indicated by the dotdash line 33 and the point 36 of the heated tool The crysmaintained at a sumciently high temperature to melt the disc 38 of solder. When the disc 38 melts, the molten material from the disc 38 will form a solder connection of conical form 31 between the end of the wire and the stripe 34 on the crystal 32. Some of the molten material will flow up the lower end of the wire 35 and some of it will slightly spread out over the stripe 34 on the crystal. When the heated tool 29 is removed from engagement with the disc 38, the solder will solidify and provide the solder connection 31 shown in Fig. 24. It will be seen that since the disc 38 is made of predetermined size and form and that because the heating tool 29 is only applied for a suillcient length of time to bring the material in thedisc 38 to a molten condition and is then removed, substantially none of the material inthe disc 38 will be lost. Furthermore, since the end of the wire is wetted by the flux and the solder therefore has a tendency to follow the flux on the wire, a solder connection of conical form is made between the wire and the metal stripe on the crystal and the crystal is not overloaded by the application of too much solder at the point of connection between the wire 35 and the metal stripe 34. After the wire 35 has been solder-connected to the crystal on one side, the wire 35 may be severed at a required point, the crystal may be then turned over on the table 98 with the projecting end of the wire remaining no the crystal extending downwardly within the aperture and the apparatus may be operated again to solder-connect an end ofthe wire 35 to a metal stripe 34 provided on the other side of the crystal. I have found that when solder connections are made with the apparatus shown and described, the solder connections are all of the same size and form and are all located at the required point on the crystal. The wire 35 is not embrittled or annealed by the heat used in making the solder connection since no electrical heating current is applied through the wire 35 such as might change the characteristic of the wire 35 and, in fact, there is no heat directly applied to the wire 35 because the heated end 36 of the heated tool 29 is not brought into engagement with the wire 35 but is only brought into .engagement with the disc 38 of solder. Since the characteristic of the wire 35 is not changed in any way in making the solder connection, the wire 35'retains its original resiliency and may be used as a resilient support for the crystal 32 as well as a conductor wire for supplying current to the crystal.

What is claimed is: A

l. The method of securing a wire to a crystal comprising cutting a disc of solder of predetermined size and form, providing on the crystal at a required point a surface of solder, applying flux to an end of the wire and to the surface of solder, thrusting the fiuxed end of the wire into the disc of solder to make the disc stick on the end of the wire, placing the disc with the wire frictionally attached thereto on the fluxed portion of the solder on the crystal, applying a heated tool having no afllnity for the solder to the disc of solder to make the solder form a solder connection between the wire and the crystal and removing the heated tool as soon as the material in the solder disc is brought to amined size and form, providing a surface of solder on the crystal at arequired point, applying a soldering flux to an end of the wire and bringing the fluxed end 01 the wire into engagement with the surface of solder on the crystal and depositing some of the flux from the wire on the surface of solder on the crystal, thrusting the fluxed end of the wire into the disc of solder to make the disc frictionally stick on the end of the wire, heating the crystal to a predetermined temperature below the melting temperature of the disc oi solder and the surface of solder on the crystal, placing the disc with the wire attached thereto on the fluxed portion or the solder surface on the crystal, applying a heated tool to the disc of solder until the disc is brought to a molten condition and then removing the heated tool from the disc of solder.

a,sos,coc

mined size and form from a sheet of solder toll.

providing a surface 01' solder on a required point on the crystal, applying flux to an end of the wire and to the surface of solder on the crystal. thrusting the fluxed end of the wire into the disc oi solder and picking up the disc of solder on the end of the wire, placing the disc with the wire attached thereto on the fluxed portion ofthe solder on the crystal and applying a heated tool having a heated tip to which solder will not adhere. to the disc 0! solder until the material in the disc of solder begins to melt and then relb moving the heated tool from the disc of solder.

WILLIAM E. INGERSON. 

